UNIX timestamp from a datetime class

[John Reese]

Hi.

import time, calendar, datetime
n= 1133893540.8749 22
datetime.dateti me.fromtimestam p(n) datetime.dateti me(2005, 12, 6, 10, 25, 40, 874922) lt= _
datetime.dateti me.utcfromtimes tamp(n) datetime.dateti me(2005, 12, 6, 18, 25, 40, 874922) gmt= _
So it's easy to create datetime objects from so-called UNIX timestamps
(i.e. seconds since Jan 1, 1970 UTC). Is there any way to get a UNIX
timestamp back from a datetime object besides the following
circumlocutions ?
float(lt.strfti me('%s')) 1133893540.0 calendar.timegm (gmt.timetuple( ))

1133893540

[gry]

John Reese wrote:

Hi.

import time, calendar, datetime
n= 1133893540.8749 22
datetime.dateti me.fromtimestam p(n) datetime.dateti me(2005, 12, 6, 10, 25, 40, 874922) lt= _
datetime.dateti me.utcfromtimes tamp(n) datetime.dateti me(2005, 12, 6, 18, 25, 40, 874922) gmt= _
So it's easy to create datetime objects from so-called UNIX timestamps
(i.e. seconds since Jan 1, 1970 UTC). Is there any way to get a UNIX
timestamp back from a datetime object besides the following
circumlocutions ?

d=datetime.date time.fromtimest amp(1133893540. 874922)
epoch = int(d.strftime( '%s'))
usec = d.microsecond
epoch + (usec / 1000000.0)

1133893540.8749 22

[Tim Peters]

[John Reese]

import time, calendar, datetime
n= 1133893540.8749 22
datetime.dateti me.fromtimestam p(n) datetime.dateti me(2005, 12, 6, 10, 25, 40, 874922) lt= _
datetime.dateti me.utcfromtimes tamp(n) datetime.dateti me(2005, 12, 6, 18, 25, 40, 874922) gmt= _
So it's easy to create datetime objects from so-called UNIX timestamps
(i.e. seconds since Jan 1, 1970 UTC). Is there any way to get a UNIX
timestamp back from a datetime object besides the following
circumlocutions ?
float(lt.strfti me('%s')) 1133893540.0 calendar.timegm (gmt.timetuple( )) 1133893540

Do

time.mktime(som e_datetime_obje ct.timetuple())

Note that datetime spans a much larger range than most "so-called UNIX
timestamp" implementations , so this conversion isn't actually possible
for most datetime values; e.g.,

time.mktime(dat etime(4000, 12, 12).timetuple() ) Traceback (most recent call last):
File "<stdin>", line 1, in ?
OverflowError: mktime argument out of range

on a Windows box. Note too that Python timestamps extend most UNIXy
ones by being floats with fractional seconds; time,mktime() doesn't
know anything about fractional seconds, and neither does
datetime.timetu ple(); e.g.,
time.mktime(dat etime.utcfromti mestamp(1133893 540.874922).tim etuple())

1133911540.0

loses the fractional part. You can add that back in if you like:

you can add that back in if you like:

time.mktime(som e_datetime_obje ct.timetuple()) + \
some.datetime_o bject.microseco nd / 1e6